Halogen-yielding compositions



Patented Nov. 4, 1947 UNITED FFECE HALOGEN-YIELDING COMPOSITIONS NoDrawing. Application June 5, 1944, Serial No. 538,879

14 Claims.

This invention relates to certain new and improved oxidizingcompositions and a method for making the same.

This is a continuation-in-part of my copending application Serial No.486,092, filed May 7, 1943.

The N,N-dichloro-disubstituted hydantoins are valuable oxidizingcompounds when dissolved in water. A large variety of disubstitutedhydantoins may be prepared from various ketones by reacting ketones withhydrocyanic acid or a cyanide, ammonia, and carbon dioxide.

For example, one suitable method is to react a ketone with hydrocyanicacid to prepare the corresponding ketone cyanhydrin and then to reactthe cyanhydrin with an ammonium carbonate solution. Such disubstitutedhydantoins react very readily with chlorine so that on chlorination byconventional methods a dichlorohydantoin is formed having the formula:

where R and R represent any organic radicals, for example, alkyl or arylgroups. For example, the lowest molecular weight member of the series is1,3-dichloro-5,5-dimethyl hydantoin which may be made by reactingacetone with hydrocyanic acid and then reacting the resulting acetonecyanhydrin with ammonium carbonate and finally chlorinating theresulting dimethyl hydantoin. Similarly, 1,3-dichloro-5-methyl-5-ethylhydantoin may be made from methyl ethyl ketone,1,3-dichloro-5-methyl-5-phenyl hydantoin from acetophenone and1,3-dichloro-5,5pentarnethylene spiro hydantoin from cyclohexanone.

The diohloro-disubstituted hydantoins have strong oxidizingcharacteristics when dissolved in water and have a relatively highoxidation potential, very close to that of sodium hypochlorite. They arethus useful for various oxidizing purposes, including bleaching and fordisinfectant and bactericidal purposes. The above-mentioneddichloro-dimethyl hydantoin is sold for such purposes under thetrade-mark name Dactin. This is the most soluble of the series, as thesolubility tends to decrease as the molecular weights of the substituentgroups R and R are increased.

However, the solubilities of all these dichlorodisubstituted hydantoinsare relatively low and for many purposes these materials do not providea suiiiciently high quantity of available active chlorine in the aqueoussolution. Also, the oxidation potential of these dichloro compounds istoo high for some purposes. It has, therefore, been desired to have achlorohydantoin having a higher solubility than the above-mentioneddichloro compounds and a lower oxidation potential and a degree ofchemical stability not lower than that of the dichloro compounds.

An object of the present invention is the preparation of all new andimproved oxidizing compositions of the chlorohydantoin type. A furtherobject is the preparation of novel N-monochlorohydantoin compounds.Still other objects will be apparent from the following description ofmy invention.

I have discovered that the N-monochlorohydantoins can be easily andcheaply prepared by reaction between a dichloro-disubstituted hydantoinof the type described above and a corresponding unchlorinateddisubstituted hydantoin. The reaction may be represented as follows:

0 HN t NCl 1 u (I) R/ R O The N-monochloro compounds thus preparedaccording to my invention have been found to have much higher solubilityand to be much more stable chemically than the corresponding dichlorocompounds. They may be utilized in alkaline solutions as Well as neutralor in mildly acidic aqueous solutions. They are also soluble in avariety of organic solvents. The oxidation potentials of theseN-monochloro compounds are much lower than that of the correspondingdichloro compounds; generally, the oxidation potential of themonochlorohydantoin is roughly half that of the corresponding dichlorocompound.

The simplest method of carrying out the above reaction to produce theN-monochloro-disubstituted hydantoins is to simply react theunchlorinated hydantoin with the dichlorohydantoin in aqueous solution,If an aqueous solution of the dichloro compound is used for thispurpose, the result of the reaction is an aqueous suspension of thecorresponding N-monochloro compound. However, it is not necessary tohave all of the dichloro compound in solution, and it is generallypreferred to make a slurry or paste of the dichloro compound with arelatively small amount of water and to mix therewith the unchlorinatedcompound. After the mixture is stirred for a sufiicient time to insuresuch reaction, which generally requires from one-half hour to severalhours, the product may be recovered by filtering or pressing to removethe bulk of the Water, followed by a conventional drying operation. Ifequimolar proportions of the dichloro compound and the unchlorinatedcompound are used, the resulting product Will be substantially pure N-monochlorohydantoin, the yield being substantially 100%. The reactionoccurs readily at relatively low temperatures, such as -30" C. and Willoccur at lower temperatures, though more slowly. Higher temperatures upto 100 C. or thereabouts may be utilized if desired, but generally thereis no advantage in using higher temperatures when the reaction iscarried out in the presence of water.

The above reaction also may be carried out by merely heating a drymixture of the reactants to a temperature at least suificiently high toform a molten mass. The minimum temperature utilized for this methodwill depend upon melting points of the reactants and the product.Generally a temperature within the range of about '75 to 150 C. will besuitable.

The above-described reaction also may be carried out in organic solventsin which the reactants are soluble. For example, various chlorinatedhydrocarbon solvents, such as carbon tetrachloride, tetrachlorethylene,chloroform, methylene chloride, tetrachlorethane and the like. As thereaction tends to go more slowly in organic solvents than in water, itis generally desirable to heat the reaction mixture, for example, to atemperature of from 50 up to the boiling point of the solvent. Thisoperation may be carried out by merely subjecting the mixture ofreactants in the organic solvent to refluxing conditions, for example,for a period of from minutes to one hour. The product then may berecovered by evaporating the solvent,

In carrying out the above-mentioned reaction, I prefer to usesubstantially equimolar proportions of the reactants in order to producea substantially pure N-monochlorohydantoin. However, the invention isnot so restricted, as for some purposes it is desirable to use an excessof either of the reactants and thus to produce a mixture of themonochloro compound with the reactant used in excess. For example, if itis desired to have an N-chloro composition having properties somewherebetween the properties of dichlorohydantoin and monochlorohydantoin, Imay carry out the reaction using an excess of the dichloro compound andthereby produce a composition which is an intimate mixture of themonochloroand dichlorohydantoins.

In accordance with my invention, I may also prepare a dry mixture of adichloro-disubstituted hydantoin with an unchlorinated disubstitutedhydantoin. This novel composition may be dissolved in water or inorganic solvents, whereupon it exhibits the properties of a solution ofthe corresponding N-monochlorohydantoin. I have found that such drycompositions have excellent chemical stability and may be stored orshipped for long periods of time substantially without loss of activechlorine content. Such compositions preferably contain equimolarproportions of a dichlorohydantoin and the corresponding unchlorinatedhydantoin but, if desired, various other proportions may be utilized,depending upon the desired properties for different purposes.

I have now found that by admixing such fir chlorohydantoin with anunchlorinated hydantoin, there is produced an active chlorine-yieldingagent having a reduced oxidation potential. The mixture is more solublein water and aqueous liquids so that a solution having a higher contentof available chlorine may be produced. The mixture in solution behavesas if part of the chlorine present in the dichlorohydantoin istransferred to the unchlorinated hydantoin, so that the end productappears to constitute, when approximately equimolar proportions of thetwo compounds are present, an N-monochloro-5,5-dimethyl hydantoin, sothat the final product is of lower chlorine percentage and reducedoxidation potential. Regardless of this, as a result of the peculiaraction of the unchlorinated hydantoin on the1,3-dichlorohydantoin, thesolubility is increased so that the resulting solution contains a higherquantity of available chlorine than can be produced by utilizing1,3-dichlorohydantoin alone.

In order to show the effect of the incorporation of the unchlorinatedhydantoin with the dichlorohydantoin on the available chlorine contentof the resulting solution, tests have shown that a solution containingdissolved therein 0.15% of 1,3-dichloro-5,5-dimethyl hydantoin, whichsolution ma be prepared in about twenty minutes with water at 25 C., isequivalent to approximately 1200 parts per million of availablechlorine. When an equimolar mixture of dimethyl hydantoin and dichlorodimethyl hydantoin is prepared I have found that it is possible underthe same conditions to bring much more than 0.16% of1,3-dichloro-5,5-dimethyl hydantoin into solution, and that at 25 C. ina period of twenty minutes it is possible to obtain a solutioncontaining 3800 parts per million of available chlorine. This is overthree times that possible under the same conditions when the dichlorocompound is dissolved alone, i. e. without the presence of dimethylhydantoin.

Moreover, the solution resulting under such circumstances when anequimolecular mixture of the dichloro dimethyl hydantoin and thedimethyl hydantoin is dissolved in water is much more stable underconditions of storage than a solution containing no dissolved5,5-dimethyl hydantoin. In'tests extending over a period of one andone-half months, both with the dry mixture of 1,3-dichloro-5,5-dimethylhydantoin and dimethyl hydantoin, and with solutions prepared bydissolving that dry mixture in Water, very little loss of activechlorine has been observed. In the case of the solutions, due toevaporation of water therefrom without equivalent loss in chlorinecontent, the percentage of active chlorine present therein has actuallybeen found to increase somewhat. In one test the initial active chlorinecontent Was 0.175%, while at the end of approximately six weeks theactive chlorine content, instead of decreasing, had actually increasedto 0.192%. In another similar test, the initial active chlorine contentof the solution was 0.168%, while at the end of six Weeks it was 0.185%.Analyses of the change in active chlorine content of the dry equimolarmixture when stored over the same period indicated a loss of onlyapproximately 2.8%, the initial active chlorine content being 22.8%while that at the end of six Weeks was 20.0%. It is, therefore, apparentthat the presence of the dimethyl hydantoin, either in the dry solidcomposition or in solutions prepared therefrom, substantially increasesthe stability thereof. This effect is, of course, not restricted tocompositions containing equimolar amounts of the div chloro andnon-chlorin containin 5,5-dimethyl compounds, asthe desirable effects ofincreased chlorine content of the solutions and greater stability, bothof the solutions and of the dry composition, are obtained when there isat least 0.5 mole of 5,5-dimethyl hydantoin present for every mole of1,3-dichloro-5,5-dimethyl hydantoin.

Reduced oxidation potential is important in certain instances where itis desired that the active. chlorine compound exerts its characteristicgermicidalv effect without bleaching the material treated to anundesired degree. Thus in treating dyedigarments, dyed fabric, etc, inorder to destroy bacteria present thereon, it is generally necessarythat the antiseptic or germicidal action be efiected without lighteningt any extent the color of the dyed garment or fabric. I have found thatmy improved active chlorine yielding mixtures comprising anunhalogenated hydantoin and dihalohydantoin in molar amounts of at least0.25 to I possess the definite advantage of reduced oxidation potentialas compared with the dihalohydantoin alone.

For example, the effect of various amounts of 5,5-dimethyl hydantoin,present in molar proportions ranging from 0.25 mole for every mole of1,3-dichloro-5,5-dimethyl hydantoin to 3.0 moles per mole of1,3-dichloro-5,5-dimethyl hydantoin, in reducing the oxidation potentialof the resulting solution is shown in the fOllOWil'lg table. It shouldbe noted that when the pH value of the solution was 6.0, a solutioncontaining 1,3-dichloro-5,5-dimethyl hydantoin alone, (no 5,5-dimethylhydantoin being present) had an oxidation potential of 0.96 volt.Similarly, at a pH of 8.0, this solution in which no dimethyl hydantoinwas present had an oxidation potential of 0.82 volt. The values securedat these two pH values when a solution was prepared by dissolving amixture containing varying amounts of the dimethyl hydantoin and thedichloro dimethyl hydantoin are evident from Table I.

TABLE I Composition of mixture of 1,3-dichZorO-5,5-dimethyl hydantoinand 5,5-dzmethyl hydantoin used in preparing solution These potentialswere determined against a saturated calomel half cell.

Various changes in the relative proportions of the two ingredientspresent in my dry stable compositions may be made without departing fromthe scope of the invention. Cf course, in addition to thedihalohydantoin and the unhalogenated hydantoin, other materials such asbuffering agents and surface tension-reducing agents may be present inthe dry mixture. Thus, sodium bicarbonate and other. substances ofsimilar alkalinity are compatible with the mixture and may be introducedin various amounts for the purpose of maintaining a pH value fallingwithin any specified range when the dry solid composition is dissolvedin water.

The invention is further illustrated by the following examples:

EXAMPLE 1 Monochloro dimethyl hydantoin To 500 cc. of water contained ina l-liter beaker was slowly added 67.2 g. (0.525 mole) of 5,5-dimethylhydantoin and 98.5 g. (0.500 mole) of i,3 -'dichloro-5,5-dimethylhydantoin. The reaction mixture was vigorously stirred at roomtemperature until two successive test samples gave the same meltingpoint, 3 to 4 hours usually being sufiicient. The resulting monochlorodimethyl hydantoin was then filtered off and dried. An 88% yield (143g.) of N-monochloro-5,5-dimethyl hydantoin melting at 149-150" C. wasobtained.

EXAMPLE 2 Moizochloro dimethyl hydantoin prepared in water 5,5-dimethylhydantoin (1075 g.) was dissolved in 8 liters of water containing 1 g.of Aerosol OT. 1,3-dichloro-5,5-dimethyl hydantoin (1576 g.) was addedand the mixture stirred at room temperature for 3 hours. The product wasfiltered off, washed thoroughly and air-dried. It melted at 147-148" C.and contained 21.75% active chlorine. Yield 94%.

EXAMPLE 3 Monochloro methyl ethyl hyd ntoin EXAMPLE 4 Monochloro methylethyl hydantoin 1,3-dichloro-5-methyl-5-ethyl hydantoin, pre' pared bythe chlorination of 1207 g. of 5-methyl- 5-ethy1 hydantoin in aqueoussodium carbonate, was suspended in 8- liters of water. 5-methyl-5- ethylhydantoin (1207 g.) and l g. lerosol CT were added, and the mixturestirred at room temperature for 15 hours. The product was filtered off,washed and air dried; it melted at 94-96 C., and contained 20.15% activechlorine. Yield 79.1%.

EXAMPLE 5 Monochloro methyl is butyl hydantoin To 12 liters of water ina 20-1iter container was slowly added 1071 g. (6.3 moles) of 5methyl-5-iso-buty1hydant0in, 143 1 g. (6.0 moles) of 1,3-dichloro-5-methyl-5-isobutyl hydantoin and 10 cc. of a 1% solution ofAerosol OT (dicctyl sodium sulfosuccinate). The reaction mixture wasstirred vigorously at room temperature until two successive test samplesgave identical melting 7 points, 4 to 5 hours usually being suificient.The resulting N-monochloro-5-methy1-5-isobutyl hydantoin was thenfiltered oil" and dried. A 94.3% yield (2314 g.) of product melting at69-70 C. was obtained.

EXAMPLE 6 Monochloro methyl isobutyl hydantoin1,3-dichloro-5-methyl-5-isobuty1 hydantoin, prepared by the chlorinationof 1135 g. of 5-methyl-5-isobutyl hydantoin, was suspended in 7.5 litersof Water containing 1 g. Aerosol OT. g5-metthyl-5-isobutyl hydantoin(1135 g.) was added, and the mixture stirred at room temperature for 6hours. I'he product, after filtering, washing and drying. melted at 6970C. and contained 17.45% active chlorine. Yield 94.5%.

EXAMPLE 7 M Oll-OChlOTO pentamethylene spir'o hydantoin To 3 liters ofwater contained in a 4-liter beaker was slowly added 168 g. (1.0 mole)of 5,5-pentamethylene spiro hydantoin and 237 g. (1.0 mole) by1,3-dichloro-5,5-pentamethylene spiro hydantoin. The reaction mixturewas vigorously stirred at room temperature until a material of constantmelting point was obtained, 3 to 4 hours usually being sufiicient. Theresulting N-monochloro-5,5-pentamethylene spiro hydantoin was thenfiltered off and dried. At 95.8% yield (388 g.) of product melting at146-8 C. was obtained. This compound has the formula:

/CH2CH2\ out 0 0:0

CH2-CH2 O=O-NH EXAMPLE 8 M onochloro pentamethylene spiro hydantoinPentamethylene spiro hydantoin (60 g.) was chlorinated in an aqueoussodium carbonate solution to yield the 1,3-dichloro derivative (M. P.126-127 0.; active Cl found 29.95%, calculated 29.95%). The wet productwas mixed with an additional 60 g. of the hydantoin in about 7 liters ofwater containing 1 g. Aerosol OT, and stirred for 2 hours at roomtemperature. The product was filtered off, washed and dried to constantweight at 80-85 C. It was found to melt at 138-14() CL, and to contain17.3% active chlorine. (Calculated for CsH11N202ClZ 17.5%.) Yield 92.5%.

EXAMPLE 9 Fusion of dimethyl hydantoin with a dichlorohydantoinmethylene chloride (500 cc.) were mixed and heated under reflux for halfan hour, during which time substantially all the solids dissolved.

8 The hot solution was clarified by filtration. On cooling, acrystalline precipitate of monochloro methyl ethyl hydantoin was formed.The product melted at 94-95" C., and contained 20.0% active chlorine(calculated for CsI-IsNzOzClZ 20.1%). Yield 89.9%.

EXAMPLE 11 Monochloro methyl isobutyl hydantoin prepared in carbontetrachloride 5-methyl-5-isobutyl hydantoin g.)1,3-dichloro-5-methyl-5-isobutyl hydantoin (239 g.) and carbontetrachloride (400 cc.) were heated under reflux for /2 hour, and theproduct recovered by cooling and evaporating the solution. It melted at69-72 C., and contained 16.9% active chlorine (calculated forCsH13N2O2Cl:17.3%). Yield 91.2%.

In carrying out the above-described reactions to produce themonochlorohydantoins and in preparing the above-described mixtures, Imay react or mix a dichloro-disubstituted hydantoin with a differentunchlorinated hydantoin. Thus, for example, I may prepare a mixture ofdichloro dimethyl hydantoin and unchlorinated methyl ethyl hydantoin.When this mixture is subjected to reacting conditions, for example, bysolution in water or other solvent or by heating to the melting point, amixture of the corresponding N-chloro compounds is formed, that is, amixture of N-monochloro dimethyl hydantoin and N-monochloro methyl ethylhydantoin. As will be apparent to the skilled chemist, various othermixtures may thus be prepared or reacted, and if desired, a plurality ofdichloro compounds may be reacted with a plurality of unchlorinatedhydantoins.

While my invention has been described above by reference to theproduction of N-monochlorohydantoins from N-dichlorohydantoins, theinvention also may be carried out by using other dihalogenatedhydantoins to make the corresponding monohalohydantoins. For example, Imay use the corresponding dibromo-, diiodo-, or difiuorohydantoins andthus produce the corresponding monobromo-, monoiodo-, andmonofiuorohydantoins.

For most purposes. the above-described N- rnonochloro dirnethylhydantoin is preferred as it has the highest solubility in water and hasexcellent oxidizing properties. However, I have found that thecorresponding N-monochloro-S- methyl-5-ethyl hydantoin and theN-monochloro- S-methyl-S-isobutyl hydantoin, which may be readilyprepared by my above-described process, are excellent oxidizing agentsand for some purposes may be preferred tothe dimethyl compound. Otherexamples of monohalo compounds which may be made by the process of myinvention are N-monochloro 5 methyl-S-n-amyl hydantoin; N-monochloro 5methyl-S-n-butyl hydantoin; N-monochloro 5 methyl-5-isobutyl hydantoin;N-monochloro 5 methyl-5-isobutylene hydantoin;N-monochloro-5-methyl-5-phenyl hydantoin; N-monochloro-5-ethyl-5-phenylhydantoin; N-monochloro-5-methyl-5-acetic acid ester hydantoin;N-monochloro 5 methy1-5-cyclohexyl hydantoin; Nmonochloro-5-pentamethylene-5- spiro hydantoin; andN-monobromo-5,S-dimcthyl hydantoin. All of these N-monohalo compoundshave properties similar to those of the corresponding N-monochlorodimethyl hydantoin, and in each case have higher solubility, a loweroxidation potential, and a higher degree of chemical stability than thecorresponding dichloro compound.

My invention is not restricted to the abovementioned Nmonochlorohydantoins, as my herein-described process may be carried outwith any of the disubstitutecl hydantoins by halogenating and thenreacting the resulting dihalo disubstituted hydantoin with anunhalogenated disubstituted hydantoin. The disubstituted hydantoinsuseful for this purpose may be derived from various ketones, forexample, dialkyl ketones, alkyl alkylene ketones, dialkylene ketones,cycloaliphatic ketones (e. g., cyclohexanone and cyclohexenone, alkylcyclohexyl ketones, and the like), alkyl aryl ketones, diaryl ketones,and various other ketonic compounds such as keto-esters, keto-acids,keto-alcohols, keto-ethers, and the like.

I claim:

1. The process for the production of an N- monochlorohydantoin, whichcomprises reacting an unchlorinated 5,5-dialkyl hydantoin containing twounsubstituted =NH groups with a substantially equimolar proportion of anN,N-dichloro-5,5-dialkyl hydantoin, both of said hydantoins having thesame alkyl groups.

2. The process for the production of an N- monochloro-5,5-dimethylhydantoin which comprises reacting 5,5-dimethyl hydantoin with asubstantially equimolar proportion of 1,3-dichloro- 5,5-dimethylhydantoin.

3. The process for the production of an N- monohalohydantoin whichcomprises reacting an unhalogenated 5,5-hydrocarbon radicaldisubstituted hydantoin having two unsubstituted =NH groups with anN,N'-dihalo-5,5-hydrocarbon radical disubstituted hydantoin.

4. The process for the production of an N- monochlorohydantoin whichcomprises reacting an unchlorinated 5,5-hydrocarbo-n radicaldisubstituted hydantoin having two unsubstituted =NH groups with asubstantially equimolar proportion of an N,N-dichloro-5,5-hydrocarbonradical disubstituted hydantoin, the 5,5-substituent groups being thesame in both of said hydantoins.

5. The process according to claim 4 carried out in the presence ofwater.

6. The process according to claim 4 in which the reactants are mixedtogether with an amount of water less than that required to completelydissolve the product and the resulting N -monochlorohydantoin isseparated from the mixture.

7. The process according to claim 4 which is carried out by heating thereactants to a temperature sufficiently high to form a molten mass andthereafter cooling said mass to solidify the reaction product.

8. The process according to claim 4 in which the reaction is carried outin the presence of a nonaqueous solvent which is substantiallychemically inert towards said reactants and the reaction product.

9. A stable, active halogen-yielding nonaqueous mixture of hydantoinsconsisting essentially of an N,N-dihalo-5,5-hydrocarbon radicaldisubstituted hydantoin and an unhalogenated 5,5-hydrocarbon radicaldisubstituted hydantoin containing two unsubstituted =NH groups, in theproportions of 0.25 to 3 moles of the unhalogenated hydantoin to onemole of the dihalohydantoin.

10. A stable, active chlorine-yielding nonaqueous mixture of hydantoinsconsisting essentially of an N,N-dichloro-5,5-hydrocarbon radicaldisubstituted hydantoin and an unhalogenated 5,5- hydrocarbon radicaldisubstituted hydantoin containing two unsubstituted =NH groups, in theproportion of 0.25 to 3 moles of the unhalogenated hydantoin to one moleof the dichlorohydantoin.

11. A stable, active chlorine-yielding nonaqueous mixture of hydantoinsconsisting essentially of an N,N'-dichloro-5,5-dialkyl hydantoin and asubstantially equimolar amount of an unhalogenated 5,5-dialkylhydantoin, the 5,5-dialkyl groups being the same in both of saidhydantoins.

12. A stable, active chlorine-yielding nonaqueous mixture of hydantoinsconsisting essentially of 0.25 to 3 moles of 1,3-dichloro-5,5-dimethylhydantoin and 1 mole of 5,5-dimethyl hydantoin.

13. A stable, active chlorine-yielding nonaqueous mixture of hydantoinsconsisting essentially of 1,3-dichloro-5,5-dimethyl hydantoin and 5,5-dimethyl hydantoin, said 5,5-dimethyl hydantoin being present therein inamounts ranging from 0.5 to 3.0 moles, per mole of 1,3-dichloro-5,5-dimethyl hydantoin.

14. A stable, active chlorine-yieldin nonaqueous mixture of hydantoinsconsisting essentially of substantially equimolar proportions of 1,3-dichloro-5,5-dimethyl hydantoin and 5,5-di1nethyl hydantoin.

PAUL LA FRONE MAGILL.

REFERENCES CITED The following references are of record in the file ofthis patent:

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Number Name Date 2,130,805 Levine Sept. 20, 1938 2,311,507 Arthur Feb.16, 1943 2,225,384 Greenacher et a1. Dec. 17, 1940 2,155,863 JacobsonApr. 25, 1939 2,354,210 Jacobson July 25, 1944 OTHER REFERENCES Journalfur Praktische Chemie, N. F., vol. 113 (1926), pages 248-249.

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Henze et al., Journal of Org. Chem., Jan. 1943, page 24.

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